Surgical staplers have been developed in recent years, and are now recognized as providing a viable alternative to suturing. Upon information and belief, the principal advantage of stapling vis-a-vis suturing lies in a saving of time on behalf of the surgeon.
Some suture materials are soluble in body fluids, while other suture materials are not. In the case of the so-called dissolving suture, the various stitches may be permanently enclosed within the body. After passage of time, normally long enough for the joined tissue to heal, the suture will gradually dissolve. Stitches of non-dissolving suture, on the other hand, must generally be physically removed.
Staples are normally formed of metal. Some metals, such as stainless steel, platinum or titanium, are generally recognized as being non-thrombogenic, and may simply be left within the patient's body. After the stapled tissue heals, the staples are no longer needed for their intended initial function, and may simply remain within the body. If they are made of a non-thrombogenic material, their retained presence within the body is not adverse.
In the past, various types of special-purpose staple guns have been developed. These various types are arrayed in "Stapling Techniques-General Surgery", Third Edition (United States Surgical Corporation 1988). Additional illustrations of prior art stapling techniques may be found in Soper et al., "A Stapled Technique for Construction of Ileal J Pouches", Surgery, Gynecology & Obstetrics (June 1988) [pp. 557-559], Kataoka et al., "Problems Associates with the EEA Stapling Technique for Esophagojejunostomy After Total Gastrectomy", Ann Surg. (January 1989) [pp. 99-103], and Brough et al., "An Improved Technique of J Pouch Construction and Ileoanal Anastomosis", Br. J. Surg. (April 1989) [pp. 350-351].
At the same time, techniques have been developed for repairing a damaged blood vessel by placement of a tubular graft therewithin. The graft itself is typically formed of suitable fabric, and is in the shape of an elongated thin-walled cylindrical tube. According to one technique, the graft may be furled upon a stylet, inserted longitudinally in a patient's blood vessel through a suitable incision in same, and, once in the desired position relative to the blood vessel, may be suitably unfurled to reassume its cylindrical shape within the blood vessel. It is thereafter necessary to secure the graft to the wall of the blood vessel. In this regard, my prior U.S. Pat. No. 4,872,874 ("Method and Apparatus for Transarterial Aortic Graft Insertion and Implantation") discloses a technique for stapling the opposite marginal end portions of such a tubular graft to the vessel wall. Basically, my earlier patent discloses, in pertinent part, a plurality of radially outwardly-facing U-shaped staples operatively held in an inflatable bulb. After the graft has been initially positioned, the deflated bulb is inserted into the blood vessel. Once in the desired position, the bulb is thereafter inflated to drive the staples radially outwardly, thereby to join the marginal end portions of the graft to the vessel wall. In that prior arrangement, when the bulb is inflated, the staples are driven radially outwardly into engagement with the vessel wall, but the legs of the staples are not bent, crimped or otherwise deformed after penetrating the graft and blood vessel. Basically, the U-shape of the staples was unchanged after the tips of the legs penetrated the graft and wall of the blood vessel.
Accordingly, there is believed to be a need for an improved surgical stapler which may be inserted longitudinally within a blood vessel (e.g., a vein or artery), or some other body tube, which may be moved longitudinally therealong to a desired location relative to the blood vessel, which may be selectively articulated relative to the longitudinal axis of the blood vessel, and which may be thereafter operated so as to, first, drive the prongs of a U-shaped staple through an object and into the blood vessel wall, and to, secondly, bend or deform the inserted staple such that the staple cannot unintentionally separate from the blood vessel wall.